Update app.py

app.py

@@ -18,10 +18,10 @@ def solve_3d_heat_equation(Lx: float, Ly: float, Lz: float,
     x = np.linspace(0, Lx, Nx)
     y = np.linspace(0, Ly, Ny)
     z = np.linspace(0, Lz, Nz)
-    dx, dy, dz = x[1] - x, y[1] - y, z[1] - z
+    dx, dy, dz = x[1] - x, y[1] - y, z[1] - z # Corrected indexing
 
     if dx == 0 or dy == 0 or dz == 0:
-        raise ValueError("Nx, Ny, and Nz must be > 1.")
+        raise ValueError("Nx, Ny, and Nz must be > 1 for valid dx, dy, dz.")
 
     # Stability condition for 3D FTCS scheme
     dt = 0.5 / (Gamma * (1/dx**2 + 1/dy**2 + 1/dz**2)) # Adjusted for 3D
@@ -44,7 +44,7 @@ def solve_3d_heat_equation(Lx: float, Ly: float, Lz: float,
         raise ValueError(f"Unknown initial condition: {initial}")
 
     U = np.zeros((Nt, Nx, Ny, Nz))
-    U = u.copy()
+    U = u.copy() # Store initial condition
 
     for n in range(1, Nt):
         un = u.copy()
@@ -83,7 +83,6 @@ def create_animation_gif_3d_slice(U, Lx, Ly, Lz, initial, bc, Gamma, frame_skip,
     Nt, Nx, Ny, Nz = U.shape
     fig, ax = plt.subplots()
     
-    # We'll animate the central xy-slice
     slice_z_idx = Nz // 2
     z_coord_slice = np.linspace(0, Lz, Nz)[slice_z_idx]
     
@@ -100,17 +99,22 @@ def create_animation_gif_3d_slice(U, Lx, Ly, Lz, initial, bc, Gamma, frame_skip,
         im.set_data(U[frame, :, :, slice_z_idx].T)
         return [im]
 
-    idx = list(range(0, Nt, frame_skip))
-    if not idx or (idx[-1]!= Nt - 1 and Nt > 1) : # Ensure last frame is included if Nt > 1
-         if Nt-1 not in idx: idx.append(Nt - 1)
-    if not idx and Nt ==1: # Handle case with only one time step
-        idx = 
+    if Nt <= 1:
+        idx =  # Only one frame (initial state)
+    else:
+        idx = list(range(0, Nt, frame_skip))
+        if not idx: # If frame_skip is too large for Nt > 1
+            idx = 
+        if idx[-1]!= Nt - 1: # Ensure last frame is included
+            idx.append(Nt - 1)
+        # Remove duplicates if Nt-1 was already included by range
+        idx = sorted(list(set(idx)))
 
 
     ani = FuncAnimation(fig, update, frames=idx, blit=True)
 
     with tempfile.NamedTemporaryFile(suffix='.gif', delete=False) as tmpfile:
-        ani.save(tmpfile.name, writer='pillow', fps=max(1, 30 // frame_skip)) # Adjust fps based on skip
+        ani.save(tmpfile.name, writer='pillow', fps=max(1, 30 // max(1,frame_skip)))
         gif_path = tmpfile.name
 
     plt.close(fig)
@@ -130,10 +134,10 @@ def create_plotly_figure_3d(u_3d, Lx, Ly, Lz, time_label):
         y=Y.flatten(),
         z=Z.flatten(),
         value=u_3d.flatten(),
-        isomin=u_3d.min(),
+        isomin=u_3d.min(), # Use actual min/max of the current data
         isomax=u_3d.max(),
-        opacity=0.1, # needs to be small to see through all surfaces
-        surface_count=20, # needs to be a large number for good volume rendering
+        opacity=0.1, 
+        surface_count=17, # Adjusted for potentially better performance/look
         colorscale='viridis'
     ))
     fig.update_layout(
@@ -141,7 +145,9 @@ def create_plotly_figure_3d(u_3d, Lx, Ly, Lz, time_label):
         scene=dict(
             xaxis_title='x',
             yaxis_title='y',
-            zaxis_title='z'
+            zaxis_title='z',
+            # Aspect ratio can be important for 3D visualization
+            aspectmode='cube' 
         )
     )
     return fig
@@ -152,7 +158,7 @@ def run_simulation_3d(lx, ly, lz, t_max, gamma, nx, ny, nz, initial, bc, frame_s
         Lx=lx, Ly=ly, Lz=lz, t_max=t_max, Gamma=gamma, 
         Nx=nx, Ny=ny, Nz=nz, initial=initial, bc=bc
     )
-    Nt = U.shape
+    Nt = U.shape # Corrected: U.shape is Nt
     
     idx0 = 0
     idx1 = round((Nt - 1) / 4) if Nt > 1 else 0
@@ -175,6 +181,8 @@ def run_simulation_3d(lx, ly, lz, t_max, gamma, nx, ny, nz, initial, bc, frame_s
 # --- Gradio Interface Logic (3D) ---
 def gradio_interface_3d(lx, ly, lz, t_max, gamma, nx, ny, nz, initial, bc, frame_skip):
     nx, ny, nz, frame_skip = int(nx), int(ny), int(nz), int(frame_skip)
+    # Ensure frame_skip is at least 1
+    frame_skip = max(1, frame_skip)
     gif_path, fig0, fig1, fig2, fig3 = run_simulation_3d(
         lx, ly, lz, t_max, gamma, nx, ny, nz, initial, bc, frame_skip
     )
@@ -188,13 +196,13 @@ with gr.Blocks(theme=gr.themes.Soft(), title="3D Heat Simulator") as demo:
             gr.Markdown("## Domain & Grid")
             lx_slider = gr.Slider(0.1, 5.0, 1.0, 0.1, label="Lx")
             ly_slider = gr.Slider(0.1, 5.0, 1.0, 0.1, label="Ly")
-            lz_slider = gr.Slider(0.1, 5.0, 1.0, 0.1, label="Lz (New)") # New
-            nx_slider = gr.Slider(3, 100, 30, 1, label="Nx") # Max reduced for 3D
-            ny_slider = gr.Slider(3, 100, 30, 1, label="Ny") # Max reduced for 3D
-            nz_slider = gr.Slider(3, 100, 30, 1, label="Nz (New)") # New, max reduced
+            lz_slider = gr.Slider(0.1, 5.0, 1.0, 0.1, label="Lz")
+            nx_slider = gr.Slider(3, 60, 20, 1, label="Nx (e.g., 20-40 for speed)") # Max reduced
+            ny_slider = gr.Slider(3, 60, 20, 1, label="Ny (e.g., 20-40 for speed)") # Max reduced
+            nz_slider = gr.Slider(3, 60, 20, 1, label="Nz (e.g., 20-40 for speed)") # Max reduced
 
             gr.Markdown("## Simulation")
-            t_slider = gr.Slider(0.01, 2.0, 0.2, 0.01, label="t_max") # Max t_max reduced
+            t_slider = gr.Slider(0.01, 1.0, 0.1, 0.01, label="t_max (e.g., 0.1-0.5)") # Max t_max reduced
             gamma_slider = gr.Slider(0.001, 1.0, 0.1, 0.001, label="Gamma")
 
             gr.Markdown("## Conditions")
@@ -206,7 +214,7 @@ with gr.Blocks(theme=gr.themes.Soft(), title="3D Heat Simulator") as demo:
             )
 
             gr.Markdown("## Animation")
-            frame_skip_slider = gr.Slider(1, 50, 10, 1, label="Frame Skip") # Default skip increased
+            frame_skip_slider = gr.Slider(1, 50, 5, 1, label="Frame Skip (e.g., 5-10)")
             run_btn = gr.Button("Run 3D Simulation", variant="primary")
             
         with gr.Column(scale=3):
@@ -225,43 +233,43 @@ with gr.Blocks(theme=gr.themes.Soft(), title="3D Heat Simulator") as demo:
     run_btn.click(fn=gradio_interface_3d, inputs=inputs_list, outputs=outputs_list)
     
     gr.Examples(
-        examples=[1.0, 1.0, 1.0, 0.2, 0.1, 20, 20, 20, "gaussian", "dirichlet", 10], # Reduced Nx,Ny,Nz for example
-            [1.5, 1.0, 0.5, 0.3, 0.05, 25, 20, 15, "sinusoidal", "periodic", 15],
-            [1.0, 1.0, 1.0, 0.1, 0.2, 30, 30, 30, "step", "neumann", 5],
+        examples=[1.0, 1.0, 1.0, 0.1, 0.1, 20, 20, 20, "gaussian", "dirichlet", 5], 
+            [1.5, 1.0, 0.5, 0.2, 0.05, 25, 20, 15, "sinusoidal", "periodic", 10],
+            [1.0, 1.0, 1.0, 0.05, 0.2, 15, 15, 15, "step", "neumann", 2],
         inputs=inputs_list,
         outputs=outputs_list,
-        fn=gradio_interface_3d
+        fn=gradio_interface_3d,
+        cache_examples=False # Consider disabling cache if examples are slow or large
     )
 
 # --- FastAPI Setup for API Endpoint (3D) ---
 app = FastAPI()
 
-# Mount Gradio app to FastAPI
 app = gr.mount_gradio_app(app, demo, path="/")
 
-# Define the simulation parameters model for 3D
 class SimulationParams3D(BaseModel):
     lx: float
     ly: float
-    lz: float # New
+    lz: float 
     t_max: float
     gamma: float
     nx: int
     ny: int
-    nz: int # New
+    nz: int 
     initial: str
     bc: str
     frame_skip: int
 
-# Custom API endpoint to run 3D simulation and return results
-@app.post("/simulate_3d") # Renamed endpoint
+@app.post("/simulate_3d") 
 def simulate_3d_api(params: SimulationParams3D):
+    # Ensure frame_skip is at least 1 for API calls too
+    params.frame_skip = max(1, params.frame_skip)
     gif_path, fig0, fig1, fig2, fig3 = run_simulation_3d(**params.dict())
     with open(gif_path, "rb") as f:
         gif_data = base64.b64encode(f.read()).decode('utf-8')
     return {
         "gif_base64": gif_data,
-        "plot0_3d_volume": fig0.to_json(), # Indicate 3D plot
+        "plot0_3d_volume": fig0.to_json(), 
         "plot1_3d_volume": fig1.to_json(),
         "plot2_3d_volume": fig2.to_json(),
         "plot3_3d_volume": fig3.to_json()